HONOLULU — Stephanie Holzwarth took one look at the swarm of seabirds on the murky water and knew immediately what lurked beneath.
"This place smells like shark soup!" she recalls telling a handful of fellow marine scientists as their Boston Whaler pulled up to Maro Reef in the northwestern Hawaiian Islands.
Holzwarth's fear was confirmed when half a dozen gray reef sharks began circling the boat just as she and dive partner Matt Dunlap prepared to roll into the water, video cameras in hand.
"The sharks fascinated me," Holzwarth recounted in an e-mail diary. "I watched them with saucer eyes, glad they were acting curious, not aggressive."
The Sept. 20 dive, which ended safely, was among hundreds researchers have made in the last month as they complete the most extensive mapping ever of the northwestern Hawaiian Islands' reefs.
The 10 mostly uninhabited islands and atolls extend over 1,200 miles from the main Hawaiian chain. They total a little more than three square miles, but their waters are home to 70% of the coral reefs in the United States.
Beyond the reach of crowds that flock to Waikiki Beach, the islands are a haven for endangered Hawaiian monk seals, sea turtles, albatrosses and other birds, and species of fish, algae and invertebrates found nowhere else.
Sharks also call these islands home--tigers, Galapagos and a host of reef sharks that divers hope are too sated by their prey to crave humans.
Federal and state agencies will use data from the monthlong expedition to draft plans to protect the reefs and the habitats they support.
"This is one of the most isolated and pristine large-scale coral reef systems left in the world," said Dave Gulko, a marine biologist with the state Department of Land and Natural Resources and a principal investigator for the Hawaii Coral Reef Initiative Research Program.
The string of tiny islands has captured the attention of President Clinton, who this year directed federal agencies to develop a quick plan for protecting the islands' underwater ecosystems. The reef expedition, a $1.7-million project, was conceived before the presidential directive but has the same goal, organizers say.
The main Hawaiian Islands account for 15% of U.S. reefs, the Florida Keys another 2%. The rest are mainly off Texas, the Virgin Islands, Puerto Rico and U.S. territories in the Pacific.
But reefs are faring poorly.
